Im an owner of a server running Direwolf20 1.6.4 having connection issues.
One of my players was having an issue where they fell through the world to bedrock. I teleported to them and ended up in their home where their character was currently standing but on his screen he was still at bedrock. At that point I started experiencing the same issues he was having however it jerked me back to where i teleported to begin with, his home. I was unable to open chests, doors, and chat was delayed on my screen. However was instant for those around me who could see and everything was coming through console at a normal time.
Then it was almost like this "lag" caught up with itself and I was able to do things, slight "lag" still which later disappeared. Then hours later I fell through the world again and now im currently stuck at bedrock, I dont have the option for creative mode anymore, I had one of my admins /kill me and it would not allow me to respawn. Ive deleted and reinstalled ftb and direwolf20 numerous times, restarted my computer, restarted the server, deleted my player file, as well as restarted my router. I keep getting "read timed out" and "Connection lost". Its almost as though im stuck in a void and sometimes it will load the chunk im on only and then kicks me.
As im typing this one of my players has logged into the same issue, falling in a void and can only see black/sky/sun. However, so far it seemed to jerk him back into his home and hes playing without issues.